An apparatus of the generic type for ageing has been disclosed by DE 20 2004 020 206.9.
Blocks, for example, surfacing elements, facade elements, sand-lime blocks, concrete blocks, bricks or clinker bricks, natural stone blocks and the like, irrespective of their material condition, are often subjected to a subsequent treatment in order to lose their artificial appearance.
Freshly produced, set concrete blocks, in particular concrete paving blocks, are subjected to such a subsequent treatment especially frequently, in the course of which the surfaces and/or the edges are struck or broken in order to adapt the appearance to natural stone in this way. To this end, a relatively large number of concrete blocks are put into a rotary drum and “rumbled” there; the surfaces and edges of the blocks striking one another and the blocks thus treated leaving the drum in an “aged” state. Such an apparatus has been disclosed by DE-A 29 22 393.
During the treatment of the concrete blocks in a rotary drum, surfaces and edges which, for example when using the aged blocks, are not visible at all in a paving are also treated. To this extent, energy and time are needlessly wasted. Furthermore, it is necessary to put the treated concrete blocks leaving the rotary drum onto a pallet for dispatching in a regular arrangement, the amount of work and time which this involves being disproportionately high.
Sorting installations for sorting the blocks are known from the prior art, these sorting installations accordingly orienting the blocks and arranging them in a pallet form. Such sorting installations involve high procurement and operating costs and also take up a corresponding amount of space.
DE 36 21 276 C2 discloses a method in which concrete blocks are put onto a plate-like base in a single layer in a regular arrangement. The exposed surfaces and the adjoining exposed edges or essentially only the edges of the concrete blocks are then struck irregularly by way of a vibrating knocking or striking device.
Due to this method, a subsequent sorting device can be dispensed with, since the production layer is not changed. Before the treatment by the knocking or striking devices, the blocks are pushed together and oriented on the plate-like base, so that the blocks fit closely against one another and there is no longer any intermediate spaces between them. The striking tools of the striking device are arranged on a movable carriage which guides said striking tools across the surfaces of the blocks, so that the free surfaces of the blocks and those edges of the blocks lying at the top are struck by the striking tools.
A disadvantage with this method, however, is that the blocks aged in this way look artificially treated and not naturally aged. The use of the method of the generic publication does not result in ideal breaking of the edges of the blocks as is obtained by the rumbling of the blocks in a rotary drum.
Disclosed by EP 0 860 258 B2 is an apparatus and a method in which the blocks are arranged in one or two layers, preferably in their production layer, between two elements, preferably plates. In this case, the bottom plate, on which the concrete blocks rest, is in interaction with a vibrating device. The blocks are set in motion by the vibrating device so that they move back and forth between the plates. In the process, the blocks strike one another and also strike the top and the bottom plate as a result of which the edges on the top side and the underside are broken. In addition, the top sides and the undersides of the blocks are struck by the respectively assigned plates. The vertical side edges of the concrete blocks and the side faces are broken or struck by the respectively adjoining concrete blocks.
It has been found in tests that the breaking of the edges is all the poorer, the larger the block to be aged is. This results from the fact that the striking angle becomes all the smaller, the larger the block put between the plates is. The small striking angle results in unfavorable breaking of the edges.
As with the ageing method by way of the rotary drum, there is the disadvantage in this case that surfaces and edges of the blocks are treated which are possibly not visible at all, as a result of which energy and time are needlessly wasted. In addition, the requisite treatment time, in particular in the case of set concrete blocks, is long and the breaking of the edges is not ideal.
The generic publication DE 20 2004 020 206.9 discloses an apparatus for the artificial ageing of blocks in which the blocks (preferably in their production layer) are placed on a base, so that the surfaces to be treated and the adjoining edges of the blocks are exposed. By way of a magnet, freely movable striking bodies (of metal) are then applied to the surface to be treated. The base on which the blocks rest is set in vibration by way of a vibrating device. The blocks and the striking bodies are, therefore, set in motion relative to one another in such a way that the striking bodies act on the surfaces and the exposed edges of the blocks.
The apparatus disclosed by DE 20 2004 020 206.9 enables rapid and effective ageing of the top side of the blocks and the adjoining, exposed edges. The striking bodies randomly hit the surface of the blocks and, therefore, strike the latter irregularly, so that an optical effect is produced which corresponds to that of a naturally aged block.
According to the ageing process, the metallic striking bodies are lifted from the surface of the blocks again by the magnet by the latter being brought close to the blocks. The block layer can be removed and a new block layer can be fed. It is a disadvantage that the magnet to be used involves high costs. A further disadvantage is that downtimes occur due to the striking bodies being put down and picked up again by the magnet and these downtimes lead to longer cycle times.
The object of the present invention is, therefore, to improve the apparatus disclosed by the generic publication for the artificial ageing of blocks, in particular to develop an apparatus and a method which permits especially cost-effective and rapid ageing of blocks.